(1) Field of the Invention
The present invention relates to a vacuum cleaner and, more particularly, to a vacuum cleaner capable of indicating a state of a dust chamber in the body of the vacuum cleaner.
(2) Description of the Prior Art
Conventionally, a vacuum cleaner having a dust chamber in its body is provided with a pressure sensor to detect a suction pressure within the body, and an indicator which indicates the suction pressure to inform a viewer of the state of dust clogging with the dust chamber in the body of the vacuum cleaner (e.g., refer to Japanese Unexamined Patent Publication No. 1136/1981).
In recent years, some vacuum cleaners have arrangements to vary a suction force corresponding to the object being cleaned, such as a carpet, a bare floor, a sofa or a curtain, so as to facilitate cleaning.
However, if such a vacuum cleaner capable of varying a suction force is provided with a pressure sensor in its body to determine the accumulated state of dust in a dust chamber from a detected pressure, the detected pressure is varied in response to the same condition of dust in the dust chamber as the suction force of the cleaner's air blower is varied, and a problem arises that there is no way to accurately inform a user of the state of dust in the dust chamber.